1. Field of the Invention
The present invention relates to a torque control bolt for a hose clamp, and more particularly to a torque control bolt configured to be coupled with a fastening bolt that tightens or releases a hose clamp, so as to prevent the hose clamp or a hose from being deformed or damaged by being clamped with excessive torque.
2. Description of the Prior Art
In general, a hose clamp is used to tighten a hose to prevent the hose from being loosened. For example, the hose may involve a hose used in a brake, an air conditioning system, a power steering system or an engine room for a vehicle to allow a flow passage of fluid or gas, or a hose fitted on a pipe or a connecting tube to allow a flow passage of fluid or gas in an industrial field.
In order to prevent the hose clamp as described above or a hose from being damaged or deformed when the hose is tightened using the hose clamp, an assembling torque may be set or visibly indicated to enable the hose clamp to be assembled with reference to the set torque in an assembling field.
However, when a technician performs an assembling work to comply with an assembly torque set at the time of designing, it is required to confirm a torque applied for tightening using a separate specific torque wrench or the like, and to separately confirm whether the assembling work is normally performed. Consequently, it is difficult to perform an efficient work.
For this reason, an impact wrench, which is electrically, hydraulically or pneumatically operated, is used to quickly tighten the hose clamp, thereby maximizing the work efficiency.
When the assembling work is performed in this manner, the tightening of the hose clamping may be quickly completed. However, upon being tightened using an electric power, hydraulic power or pneumatic power, the hose clamp may be frequently clamped by a torque that exceeds a limit torque as well as an optimum assembling torque set at the time of designing the hose clamp.
When the hose clamp is clamped by a torque exceeding the limit torque, the hose clamp and the hose tightened by the hose clamp may be damaged. Consequently, it is difficult to maintain the hose clamp and the hose at a normal condition after the clamping or tightening is completed. Furthermore, it is also difficult to visually confirm a damaged or ruptured condition during the assembling process. As a result, a problem may be caused in that fluid or gas may leak out in the process of using the hose clamp or hose in the practically assembled state.
In order to solve this problem, a torque control cap has been developed and used which enables a hose clamp to be assembled by an assembling torque which is set at the time of designing the hose clamp, even if the hose clamp is assembled using a specific assembling tool, such as an impact wrench in an assembling field. Korean Patent Application No. 2011-0100136 filed in the name of the assignee of the present application discloses a torque control cap for a hose clamp as illustrated in FIG. 11.
Referring to FIG. 11, a torque control cap 1 for a hose clamp includes: a fastening tip 4 configured to be engaged with a head 3 of a fastening bolt 2 to transmit a clamping force of an assembling tool to the fastening bolt 2, the fastening bolt 2 being configured to decrease or increase the diameter of the hose clamp; and rupture sections 5 formed on the head 3 and the fastening tip 4 and configured to be ruptured when a force exceeding a set (assembling) torque for tightening the hose at an optimum condition is transmitted to the fastening bolt 2, thereby preventing the tightening force from being transmitted to the fastening bolt 2 anymore.
In the prior art as set forth above, rupture protrusions and rupture recesses are formed on the head of the fastening bolt and the fastening tip so that they are kept engaged with each other prior to tightening the hose clamp by the fastening bolt. However, since the rupture protrusions and the rupture recesses are merely engaged with each other, it is difficult to keep the engaged condition without strictly controlling the sizes of the rupture protrusions and the rupture recesses.
In other words, since the rupture protrusions and the rupture recesses are configured to be merely engaged with each other, the assembly of the rupture protrusions and the rupture recesses in this manner is enabled only when the they are precisely controlled in terms of size. Such a precise size control may produce a lot of defective products, and the rupture protrusions and the rupture recesses are not smoothly engaged with each other in the process of assembling a produced bolt head and fastening tip. Thus, the bolt head and the fastening tip are assembled by hitting any of them with a rubber hammer. Such a rubber hammer is used to reduce the impact and damage. However, in this process, when the rupture protrusions and the rupture recesses are not aligned to be in line with each other, respectively, the rupture sections may be easily ruptured or damaged. As a result, the assembly is difficult, and the productivity is remarkably deteriorated.
That is, when the fastening bolt and fastening tip are stored or transported in the state where the rupture sections are engaged with each other, the fastening bolt and fastening tip may be easily and frequently separated from each other due to vibration or impact produced in the process of moving them. Furthermore, the rupture sections may be fractured by impact. In a case where the rupture sections were already fractured prior to practically performing an assembling process in an assembling field, it may be impossible to fasten the fastening bolt with the set assembling torque.
After the hose clamp is tightened, the fastening tip may be separated but the rupture protrusions formed on the fastening tip and engaged in the rupture recesses formed in the head of the fastening bolt are not separated directly after assembling. However, the rupture protrusions may be separated from the rupture recesses and escape due to vibration or the like in the process of practical use, and may penetrate into various components of an industrial equipment or an engine, thereby causing a damage or trouble.